A hand-held calculator is an important and useful device. Similar to a computer, the hand-held calculator has a processor, a memory, a display, and an input device; however, there are important distinguishing differences between the hand-held calculator and the computer.
The hand-held calculator is a specialized device and not a general purpose device, as is true of a computer. Because of this specialization, typically the hand-held calculator costs less, has a longer useful lifespan, and is more reliable and more portable than the computer.
Whereas a general purpose computer is capable of executing many different programs, a hand-held calculator typically executes a single program and less frequently supports execution of user-created programs. Normally, a hand-held calculator supports addition, subtraction, multiplication, and division of numbers, either integer-based or decimal-based, entered by a user and displays the results on a built-in display.
It is known in the art to use an RS-232 serial connection between a calculator device and other devices, e.g., computer systems, data logging systems, data display systems, etc.
Disadvantageously, the RS-232 serial connection supports communication with only one device at a time. Devices must be plugged and unplugged in order to change connections increasing a frustration level of a user. Further, the RS-232 serial connection is limited to a data rate of 115 Kbits/second.